title: Modulation of B-cell exosome proteins by gamma herpesvirus infection.
abstract: The human gamma herpesviruses, Kaposi sarcoma-associated virus (KSHV) and EBV, are associated with multiple cancers. Recent evidence suggests that EBV and possibly other viruses can manipulate the tumor microenvironment through the secretion of specific viral and cellular components into exosomes, small endocytically derived vesicles that are released from cells. Exosomes produced by EBV-infected nasopharyngeal carcinoma cells contain high levels of the viral oncogene latent membrane protein 1 and viral microRNAs that activate critical signaling pathways in recipient cells. In this study, to determine the effects of EBV and KSHV on exosome content, quantitative proteomics techniques were performed on exosomes purified from 11 B-cell lines that are uninfected, infected with EBV or with KSHV, or infected with both viruses. Using mass spectrometry, 871 proteins were identified, of which ∼360 were unique to the viral exosomes. Analysis by 2D difference gel electrophoresis and spectral counting identified multiple significant changes compared with the uninfected control cells and between viral groups. These data predict that both EBV and KSHV exosomes likely modulate cell death and survival, ribosome function, protein synthesis, and mammalian target of rapamycin signaling. Distinct viral-specific effects on exosomes suggest that KSHV exosomes would affect cellular metabolism, whereas EBV exosomes would activate cellular signaling mediated through integrins, actin, IFN, and NFκB. The changes in exosome content identified in this study suggest ways that these oncogenic viruses modulate the tumor microenvironment and may provide diagnostic markers specific for EBV and KSHV associated malignancies.
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Meckes
authors.forename: Harsha P
authors.initials: HP
authors.lastname: Gunawardena
authors.forename: Robert M
authors.initials: RM
authors.lastname: Dekroon
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Heaton
authors.forename: Rachel H
authors.initials: RH
authors.lastname: Edwards
authors.forename: Sezgin
authors.initials: S
authors.lastname: Ozgur
authors.forename: Jack D
authors.initials: JD
authors.lastname: Griffith
authors.forename: Blossom
authors.initials: B
authors.lastname: Damania
authors.forename: Nancy
authors.initials: N
authors.lastname: Raab-Traub
mesh_terms: D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002470:Cell Survival; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D055354:Exosomes / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D019288:Herpesvirus 8, Human / Q000378:metabolism*; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism*; D014176:Protein Biosynthesis; D012514:Sarcoma, Kaposi / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D015398:Signal Transduction
chemical_list: D009363:Neoplasm Proteins
keywords: microparticles; microvesicles; oncosomes